#include <stdio.h>

long fibonacci(long n) {
    if (n <= 1) return n;
    return fibonacci(n - 1) + fibonacci(n - 2);
}

int main() {
    long n;
    printf("请输入要计算的 Fibonacci 数字: ");
    scanf("%ld", &n);
    printf("%ld\n", fibonacci(n));
    return 0;
}
